1. Field of the Invention
This invention relates generally to a system and method for providing roadway lane sensing for a vehicle traveling in the lane and, more particularly, to a system and method for providing roadway lane sensing on a vehicle traveling within the lane, where the lane sensing system employs an algorithm that uses a top-down view image generated from four cameras that provide images all the way around the vehicle.
2. Discussion of the Related Art
Modern vehicles are becoming more autonomous, i.e., vehicles are able to provide driving control with less driver intervention. Cruise control systems have been on vehicles for a number of years where the vehicle operator can set a particular speed of the vehicle, and the vehicle will maintain that speed without the driver operating the throttle. Adaptive cruise control systems have been recently developed in the art where not only does the system maintain the set speed, but also will automatically slow the vehicle down in the event that a slower moving vehicle is detected in front of the subject vehicle by using various sensors, such as radar and cameras. Modern vehicle control systems may also include autonomous parking where the vehicle will automatically provide the steering control for parking the vehicle, and where the control system will intervene if the driver makes harsh steering changes that may affect vehicle stability and lane centering capabilities, where the vehicle system attempts to maintain the vehicle near the center of the travel lane.
As vehicle systems improve, vehicle's will become more autonomous with the goal being a completely autonomously driven vehicle. Future vehicles will likely employ autonomous systems for lane changing, passing, turns away from traffic, turns into traffic, etc. As these systems become more prevalent in vehicle technology, it will also be necessary to determine what the driver's role will be in combination with these systems for controlling vehicle speed, steering and overriding the autonomous system.
Current vehicle lane sensing systems typically use vision systems to sense the vehicle travel lane and drive the vehicle in the lane-center. Many of these known lane sensing systems detect lane-markers on the road for various applications, such as lane departure warning (LDW), lane keeping (LK), lane centering (LC), etc., and have typically employed a single camera, either at the front or rear of the vehicle, to provide the images that are used to detect the lane-markers. However, there are various situations where a single camera may not be able to detect the lane-markers, including a low sun angle, non-visible lane markings as a result of close proximity vehicles, such as in congested traffic situations, camera failure, etc. For example, when a leading-vehicle is too close to the subject vehicle, due to traffic congestion or other traffic situations, the camera may not detect the lane-markers because the lane-markers are hidden by the leading-vehicle, and thus, lane-marker detection of the lane will fail.
It has been proposed in the art to provide a surround view camera system on a vehicle that includes a front camera, a rear camera and left and right side cameras, and that generates a top-down view of the vehicle and surrounding areas using the images from the cameras, where the images would overlap each other at the corners of the vehicle. The top-down view can be displayed for the vehicle driver to see what is surrounding the vehicle for back-up, parking, etc.